Seeking recommendations for DAC to amplifier balanced XLR cable

The amplifier is Musical Fidelity M6si and the new DAC is RME ADI-2 DAC FS, both great devices. At first I connected them with AQ Colorado 1m RCA. I happen to believe, however, that balanced cabling, which is possible between these two devices, has theoretical advantages over single-ended. I ordered Sommer Epilogue XLR cable from Germany, plugged it in yesterday and compared... Unfortunately AQ Colorado beats the newcomer. I have 2 choices: stay with AQ Colorado RCA (since it already plays great) or look for a better XLR cable. Any advice here is welcome!